KR20140116868A - Biodegradable sheet - Google Patents

Abstract

The present invention relates to a biodegradable sheet made from a biodegradable material comprising a gas barrier material, wherein the gas barrier material can be a nanoclay and / or polyvinyl alcohol.

Description

Biodegradable sheet {BIODEGRADABLE SHEET}

The present invention relates to a composition for a biodegradable sheet comprising a gas barrier material. The present invention relates to the use of nanoclay and / or PVOH as a gas barrier.

The use of biodegradable materials has grown over the years due to the environmental friendliness of biodegradable materials. The use of these materials is extensive and includes various types of plastic bags, diapers, balloons and even sunscreens. In response to the demand for more environmentally friendly packaging materials, a number of new biopolymers have emerged that appear to be biodegradable when left in the environment. Some of the largest participants in the biodegradable plastics market include well-known chemical companies such as DuPont, BASF, Cargill-Dow polymers, Union Carbide, Bayer, Monsanto, Mitsui and Eastman Chemical. Each of these companies developed one or more classes or types of biopolymers. For example, both BASF and Eastman Chemical have developed biopolymers, both known as "aliphatic-aromatic" copolymers, sold under the trade names ECOFLEX and EASTAR BIO, respectively. Bayer has developed a polyester amide called BAK. Du Pont has developed BIOMAX, a modified polyethylene terephthalate (PET). Cargill-Dow has sold several biopolymers based on polylactic acid (PLA). Monsanto discloses a polymer known as polyhydroxyalkanoate (PF1A), which includes polyhydroxybutyrate (PHB), polyhydroxyvalerate (PFJV), and polyhydroxybutyrate-hydroxyvalerate copolymer Developed a class of. Union Carbide manufactures polycaprolactone (PCL) under the trade name TONE.

Each of the biopolymers described above has unique characteristics, advantages and disadvantages. For example, biopolymers such as BIOMAX, BAK, PHB and PLA tend to be strong, but also very rigid or even weak. This makes them unsuitable candidates when a flexible sheet or film is desired, e.g., for use in the manufacture of wraps, bags, and other packaging materials that require good warp and foldability. In the case of BIOMAX, currently DuPont does not provide the proper specifications or conditions for blow molding the film from it, indicating that the film can not be considered to be blown from BIOMAX and similar polymers at present.

On the other hand, biopolymers such as PHBV, ECOFLEX and EASTAR BIO are several times more flexible than the more rigid biopolymers discussed above. However, they have a relatively low melting point, whereby they are self-adhesive and unstable when freshly processed and / or exposed to heat. It is typically necessary to include small amounts (e.g., 0.15 wt%) of silica, talc, or other filler to prevent self-sticking (or "blocking") of such films.

It is also generally difficult or even impossible to identify a single polymer or copolymer that satisfies all, or almost all, of the desired performance criteria for a given application due to the limited number of biodegradable polymers. Because of these and other reasons, biodegradable polymers are not as widely used as desired in the food packaging field, especially in the liquid container field for economic reasons.

In addition, currently known biodegradable sheets are mostly opaque, have low light transmittance and high haze. In addition, the known biodegradable sheets include those having both a high oxygen transmission rate and a high water vapor transmission rate, both of which do not contain a barrier or which are such that the sheet is generally highly permeable to gas, It can not be used as a beverage container. In addition, the physical strength of known biodegradable sheets, as measured by such parameters as stress at maximum load, strain at break and Young's modulus, is insufficient and is therefore undesirable when used in packaging, especially when it is packed with liquid.

Accordingly, there is a need in the art for a biodegradable sheet that is flexible, but physically strong, and also has low gas permeability, high translucency, and low haze. Such a biodegradable sheet could be used as a long-term container.

In addition, many liquid containers are used in the food and beverage industry, but biodegradable containers are not widely used. U.S. Pat. No. 6,422,753 discloses a separate beverage container package for drinking and refrigeration liquids, wherein the packages comprise a plurality of individual beverage container units arranged in a side-by-side manner with respect to each other. Each beverage container unit has an inner fluid chamber defined by a lower thermal weld, an upper thermal weld, and two vertical heat welds formed on opposed sheets of plastic. The heat welds between the intermediate beverage container units are provided with perforated strips and at the upper end of each container unit a tear strip on the perforation line is removed from the individual beverage container unit, There is provided an upper horizontal heat weld disposed on a tapered crimp having a gap defining a width of the upper horizontal heat weld. However, this packaging is not environmentally friendly.

U.S. Pat. No. 5,756,194 discloses a water resistant starch product useful in the food industry, including an inner core of gelatinized starch, an intermediate layer of natural resin, and an outer layer of water-resistant biodegradable polyester. Gelatinized starches are biodegradable, such as poly (beta-hydroxybutyrate-co-valerate) (PHBV), poly (lactic acid) (PLA), and poly (di- elect cons.-caprolactone) It can be made water-resistant by coating with polyester. Attachment of the two different substances is achieved through the use of intermediate layers of resinous materials such as shellac or rosin with solubility parameters (hydrophobic) that are moderate for starch and polyester. The coating is achieved by spraying an alcoholic solution of shellac or rosin over the starchy material followed by coating with a solution of the polyester in a suitable solvent. However, these products were not designed to be optimally transported by the user during physical activity. In addition, they are not designed to provide different liquid volumes that can be consumed according to instantaneous needs.

The prior art mentioned above is defective with regard to the failure to provide a simple, effective and practical packaging structure for the liquid, which allows the user to easily access the flexible, compartmentalized packaging for the liquid. As a result, there is a need for new and improved types of biodegradable liquid containers.

One embodiment of the present invention relates to a biodegradable sheet comprising a gas barrier material. In some embodiments, the gas barrier material is a nanoclay, and in another embodiment the gas barrier material is polyvinyl alcohol (PVOH), and in a further embodiment the gas barrier material is a combination of nanoclay and PVOH.

Another embodiment of the present invention relates to a container unit made from a biodegradable sheet comprising a gas barrier material, the container unit comprising a liquid storage compartment and means for removing liquid therefrom. In some embodiments, the container unit includes a latch.

These and other features and advantages of the present invention will become better understood with reference to the following drawings, which are given by way of illustration and not by way of limitation, for purposes of explaining the preferred embodiments of the present invention.
1 shows a configuration of an array of container units of different volumes according to an embodiment of the present invention.
2A shows a layout of single container units according to an embodiment of the present invention.
Figures 2b and 2c illustrate the use of single container units according to another embodiment of the present invention.
FIG. 2D illustrates the layout of an internal straw piece according to an embodiment of the present invention.
Figure 2e illustrates a cross-sectional view of a sealed inner straw segment in accordance with one embodiment of the present invention.
Figures 3A-3F illustrate the layout of an array of six container units in accordance with one embodiment of the present invention.
Figures 4A-4C illustrate the layout of single container units with a paired cover according to another embodiment of the present invention.
4D is a cross-sectional view of an upper cover sealing structure according to another embodiment of the present invention.
Figures 5A and 5B illustrate the layout of single container units with a foldable straw in the pivot according to another embodiment of the present invention.
6A-D illustrate an array of four container units according to an embodiment of the present invention, wherein the container units are all closed (FIG. 6A is a schematic view of the array, FIG. 6B is a front view of the array, 6D is a top view of the array).
Figures 7a-d illustrate an array of four container units according to an embodiment of the present invention, wherein all of the container units are open (Figure 7a is a schematic view of the array, Figure 7b is a front view of the array, 7D is a top view of the array).
8 is a graph showing the biodegradability of a three-layer sheet produced according to an embodiment of the present invention.

In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures, and components have not been described in detail so as not to obscure the present invention.

The term "biodegradable " as used herein should be understood to include polymers that degrade through the action of living organisms, light, air, water, or a combination thereof. Such biodegradable polymers include various synthetic polymers such as polyesters, polyester amides, polycarbonates, and the like. Semisynthetic polyesters derived from nature (e. G., From fermentation) can also be included in the term "biodegradable ". Biodegradable reactions are typically enzyme-catalyzed and generally occur in the presence of moisture. Natural macromolecules containing hydrolysable bonds such as proteins, cellulose and starches are generally susceptible to biodegradation by hydrolysable enzymes of microorganisms. However, a small number of artificial polymers are also biodegradable. The hydrophilic / hydrophobic nature of the polymers has a significant impact on their biodegradability and as a general rule more polar polymers can be more easily biodegraded. Other important polymeric properties that affect biodegradability include crystallinity, chain flexibility, and chain length.

The term "sheet " as used herein should be understood to have the customary meaning used in the field of thermoplastics and packaging. The biodegradable composition according to the present invention can be used to produce a wide range of articles of manufacture, including articles useful for packaging solid and liquid materials, including food materials. Thus, the sheet according to the invention comprises sheets having a wide thickness (both measured and calculated thicknesses).

The term " about "as used herein should be understood to refer to a 10% deviation from the stated value.

The term "particle" or "particulate filler" should be broadly interpreted as including filler particles having a variety of different shapes and aspect ratios. Generally, "particles" are solids having an aspect ratio (i.e., a ratio of length to thickness) of less than about 10: 1. Solids having aspect ratios in excess of about 10: 1 can be better understood as "fibers ", and these terms will be defined and discussed below.

The term "fiber" should be interpreted as a solid having an aspect ratio of at least about 10: 1. Therefore, the fiber can give better strength and toughness than the particulate filler. As used herein, the terms "fiber" and "fibrous material" include both inorganic and organic fibers.

Apart from what may be biodegradable, it is generally important that the polymer or polymer blend exhibit certain properties. The intended use of a particular polymer blend will predominantly indicate that the properties are essential for a particular polymer blend, or an article made therefrom, to exhibit desirable performance criteria. Preferred performance criteria for biodegradable sheets for use as packaging materials, especially liquid containers, may include stress at break strain, Young's modulus and maximum load.

Several measurements have been used to limit the properties of the biodegradable sheet of the present invention. Stress, Young's modulus and fracture strain at maximum load were measured using the ASTM D882-10 standard test for the tensile properties of thin plastic sheets. Transparency and haze were measured using the ASTM D1003-07el standard test for haze and luminescent transparency of the clear plastic. The oxygen permeability of biodegradable sheets was measured using the ASTM D3985-05 (2010) el standard test for oxygen gas permeability through plastic films and sheets using electrolytic sensors. The water vapor permeability of the biodegradable sheet of the present invention was measured using the ASTM E398-03 (2009) el standard test on the water vapor transmission rate of the sheet material using mechanical relative humidity measurement.

In one embodiment of the present invention, the present invention provides a biodegradable sheet having a stress at a maximum load of at least 15 MPa. According to another embodiment, the present invention provides a biodegradable sheet having a stress at a maximum load of at least 30 MPa. According to some embodiments of the present invention, the stress at maximum load is in the range of 15-50 MPa. According to some embodiments of the present invention, the stress at maximum load is in the range of 15-20 MPa. According to some embodiments of the present invention, the stress at maximum load is in the range of 20-25 MPa. According to some embodiments of the present invention, the stress at maximum load is in the range of 25-30 MPa. According to some embodiments of the present invention, the stress at maximum load is in the range of 30-30 MPa. According to some embodiments of the present invention, the stress at maximum load is in the range of 35-40 MPa. According to some embodiments of the present invention, the stress at maximum load is in the range of 40-45 MPa. According to some embodiments of the present invention, the stress at maximum load is in the range of 45-50 MPa. According to a further embodiment of the invention, the stress at maximum load is in the range of 24-26 Mpa. According to a further embodiment of the invention, the stress at maximum load is in the range of 46-48 MPa. According to a further embodiment of the invention, the stress at maximum load is in the range of 32-34 MPa. According to some embodiments of the present invention, the stress at maximum load is in the range of 19-21 MPa. According to some embodiments of the present invention, the stress at maximum load is in the range of 29-31 MPa.

The biodegradable sheet of the present invention has a breaking strain of at least 280%. According to a further embodiment, the breaking strain is at least 300%. According to some embodiments, the breaking strain is in the range of 400-600%. According to some embodiments, the breaking strain is in the range of 280-850%. According to some embodiments, the breaking strain is in the range of 280-350%. According to a further embodiment, the breaking strain is in the range of 350-450%. According to a further embodiment, the breaking strain is in the range of 450-550%. According to a further embodiment, the breaking strain is in the range of 550-650%. According to a further embodiment, the breaking strain is in the range of 650-750%. According to a further embodiment, the breaking strain is in the range of 750-850%. According to a further embodiment, the breaking strain is in the range of 410-420%. According to a further embodiment, the breaking strain is in the range of 725-735%. According to a further embodiment, the breaking strain is in the range of 575-585%. According to a further embodiment, the breaking strain is in the range 555-565%. According to a further embodiment, the breaking strain is in the range of 615-625%.

The Young's modulus of the biodegradable sheet of the present invention is at least 200 MPa. According to some embodiments of the present invention, the Young's modulus is in the range of 200-800 MPa. According to a further embodiment of the present invention, the Young's modulus is in the range of 400-600 MPa. According to a further embodiment, the Young's modulus is in the range of 300-350 MPa. According to a further embodiment, the Young's modulus is in the range of 350-400 MPa. According to a further embodiment, the Young's modulus is in the range of 400-450 MPa. According to a further embodiment, the Young's modulus is in the range of 450-500 MPa. According to a further embodiment, the Young's modulus is in the range of 500-550 MPa. According to a further embodiment, the Young's modulus is in the range of 550-600 MPa. According to a further embodiment, the Young's modulus is in the range of 600-650 MPa. According to a further embodiment, the Young's modulus is in the range of 650-700 MPa. According to a further embodiment, the Young's modulus is in the range of 700-750 MPa. According to a further embodiment, the Young's modulus is in the range of 750-800 MPa. According to a further embodiment, the Young's modulus is in the range of 675-685 MPa. According to a further embodiment, the Young's modulus is in the range of 565-575 MPa. According to a further embodiment, the Young's modulus is in the range of 600-610 Mpa. According to a further embodiment, the Young's modulus is in the range of 670-680 Mpa. According to a further embodiment, the Young's modulus is in the range of 385-395 Mpa.

According to some embodiments of the present invention, the translucency of the biodegradable sheet of the present invention is at least 75%. According to a further embodiment, the light transmittance is in the range of 75-95%. According to a further embodiment, the translucency is in the range of 75-80%. According to a further embodiment, the translucency is in the range of 80-85%. According to a further embodiment, the translucency is in the range of 85-90%. According to a further embodiment, the translucency is in the range of 90-95%. According to a further embodiment, the light transmittance is at least 95%.

According to some embodiments of the present invention, the biodegradable sheet of the present invention has an oxygen permeability of less than 8500 cc / m < 2 > / 24 hours. According to a further embodiment, the oxygen permeability is in the range of 100-130 cc / m2 / 24 hours. According to a further embodiment, the oxygen permeability is in the range of 100-1000 cc / m2 / 24 hours. According to a further embodiment, the oxygen permeability is in the range of 1000-2000 cc / m2 / 24 hours. According to a further embodiment, the oxygen permeability is in the range of 2000-3000 cc / m < 2 > / 24 hours. According to a further embodiment, the oxygen permeability is in the range of 3000-4000 cc / m2 / 24 hours. According to a further embodiment, the oxygen permeability is in the range of 4000-5000 cc / m2 / 24 hours. According to a further embodiment, the oxygen permeability is in the range of 5000-6000 cc / m < 2 > / 24 hours. According to a further embodiment, the oxygen permeability ranges from 6000-7000 cc / m2 / 24 hours. According to a further embodiment, the oxygen permeability ranges from 7000-8000 cc / m2 / 24 hours.

According to some embodiments of the present invention, the water vapor transmission rate of the biodegradable sheet of the present invention is less than 30 gr / m 2 / day. According to a further embodiment of the present invention, the water vapor transmission rate of the biodegradable sheet of the present invention is less than 20 gr / m 2 / day. According to a further embodiment, the water vapor transmission rate of the biodegradable sheet of the present invention is in the range of 15-20 gr / m 2 / day. According to a further embodiment, the water vapor transmission rate of the biodegradable sheet of the present invention is in the range of 20-25 gr / m 2 / day. According to a further embodiment, the water vapor transmission rate of the biodegradable sheet of the present invention is in the range of 25-30 gr / m 2 / day.

The present invention also relates to a biodegradable sheet comprising a suitable amount of a suitable biodegradable polymer capable of providing a biodegradable sheet having desirable physical properties as described in detail above. According to some embodiments, the biodegradable sheet of the present invention can be recycled, i.e. the material from which the biodegradable sheet is made can be reused to make additional articles of manufacture (after appropriate treatment, Milling, heating, etc.).

According to a further embodiment, the biodegradable sheet of the present invention is perishable.

According to some embodiments, biodegradable sheets include synthetic polyesters, semi-synthetic polyesters made by fermentation (e.g., PHB and PHBV), polyester amides, polycarbonates, and polyester urethanes. In another embodiment, the biodegradable sheet of the present invention comprises at least one of a number of natural polymers and derivatives thereof such as starches, celluloses, other polysaccharides, and polymers comprising or derived from the proteins.

According to some embodiments, the biodegradable sheet comprises a polylactic acid (PLA) or derivative thereof, such as CPLA, polybutylene succinate (PBS), polybutylene succinate adipate (PBSA), polyethylene succinate (PES) Poly (butylene adipate-co-terephthalate (PBAT), thermoplastic starch (TPS), polyhydroxybutyrate (PTAT), polyhydroxyalkanoate (PHB), polyhydroxyvalerate (PHV), polyhydroxybutyrate-hydroxyvalerate copolymer (PHBV), polycaprolactone (PCL), ecoflex (R), aliphatic-aromatic copolymers, Eastar Bio Aliphatic-aromatic copolymers, Bak® with polyester amides, Biomax®, modified polyethylene terephthalate, novamont®, or combinations thereof.

According to some embodiments, the biodegradable sheet comprises a polymer selected from the group consisting of polybutylene succinate adipate (PBSA), polyethylene succinate (PES), poly (tetramethylene-adipate-coterephthalate (PTAT), polyhydroxyalkanoate PHA), poly (butylene adipate-co-terephthalate (PBAT), thermoplastic starch (TPS), polyhydroxybutyrate (PHB), polyhydroxyvalerate (PHV), polyhydroxybutyrate- Bak®, a modified polyethyleneterephthalate, Biomax®, which is a late copolymer (PHBV), polycaprolactone (PCL), ecoflex®, aliphatic-aromatic copolymers, Eastar Bio®, other aliphatic-aromatic copolymers, polyesteramides (PLA) or derivatives thereof and / or polybutylene succinate (PBS) together with any of the above, novamont (R), novamont (R), or a combination thereof.

According to some embodiments, the PLA is a homopolymer. According to a further embodiment, the PLA is copolymerized with a glycolide, lactone or other monomer. One particularly attractive feature of PLA-based polymers is that they are derived from renewable agricultural products. In addition, lactic acid has asymmetric carbon atoms and thus exists in several isomeric forms. The PLA used in accordance with some embodiments of the present invention includes poly-L-lactide, poly-D-lactide, poly-DL-lactide, or combinations thereof.

According to some embodiments, the biodegradable sheet of the present invention further comprises suitable additives. According to one embodiment, the additive softens the biodegradable polymer. The softening agent used may be selected from the group comprising paraloid®, sukano®, tributyl acetyl citrate (A4®) or a combination thereof.

According to some embodiments, the biodegradable sheet of the present invention comprises at least one nanoclay and / or at least one nanocomposite. The addition of the nanoclay and / or nanocomposite reduces the water vapor transmission rate and the oxygen permeability of the biodegradable sheet of the present invention, and thus acts as a barrier in the sheet. Also, according to certain embodiments of the present invention, the nanoclay and nanocomposite added to the biodegradable sheet are naturally occurring materials, and thus the sheet remains biodegradable. According to one embodiment, montmorillonite, vermiculite or a combination thereof is added to the composition of the biodegradable sheet.

According to one embodiment, a nanoclay based on montmorillonite with a polar lipophilic surface treatment and / or a nanoclay based on a heat treated and polar lipophilic surface treated vermiculite is added to the biodegradable composition to produce a well dispersed material . According to one embodiment, the nanoclay-based gas barrier is dispersed in the bulk of the biodegradable composition and is preferably added during the melt-forming process. Dispersion of the nanoclay platelets leads to a long and complicated path in the bulk of the composition, resulting in a reduction in gas permeation rate through the resulting biodegradable sheet. According to another embodiment, the nanoclay-based gas barrier is applied to the inner gas barrier layer in a multi-layer biodegradable sheet wherein the barrier layer reduces the gas permeability.

According to one embodiment, nanoclays added to biodegradable sheets produce long, complex structures that resist moisture, oil, grease and gas infiltration such as oxygen, nitrogen and carbon dioxide. In accordance with one embodiment of the present invention, the nanoclay is based on nano-kaolin. According to another embodiment, the nanoclay added to the biodegradable sheet is based on bentonite, which is an absorbable aluminum phyllosilicate. According to one embodiment, the nanoclay is based on Cloisite (R). According to one embodiment, a mixture of suitable nanoclays may be added to the biodegradable sheet.

According to one embodiment, the nanoclay is dispersed in the bulk of the biodegradable composition, resulting in the nanoclay being dispersed in at least one layer of the biodegradable sheet. According to some embodiments, the nanoclay is added during the melt compounding process. According to another embodiment, the nanoclay is added to the biodegradable sheet in a separate layer, along with the biodegradable polymer, thereby forming a nanocomposite layer. According to one embodiment, the nanoclay layer in the multilayer biodegradable sheet is an inner layer, i.e. it is not exposed to the external atmosphere.

According to one embodiment, the nanoclay is dispersed in the bulk of the biodegradable composition, and polymer conjugation is used on the nanoclay surface to form a homogeneous dispersion. In one embodiment of the invention, the nanoclay particles contain siloxane and hydroxyl groups, which are used as functional fixatives between the inorganic nanoclay particles and the organic polymer. According to some embodiments of the present invention, the polymer may be conjugated using a heterobifunctional molecule, such as isocyanatopropyltriethoxysilane, wherein the ethoxysilane is condensed to form a silicon bond And the isocyanate group reacts further with the hydroxyl or amine group of the polymer.

According to some embodiments of the present invention, the nanoclay particles are stripped using 3- (dimethylamino) -1-propylamine (DMPA), where the tertiary amine is conjugated with hydroxyl at the surface, Amines are free for further reaction. In the next step, a bifunctional isocyanate such as hexamethylene diisocyanate (HDI), methylene diphenyl diisocyanate (MDI) or toluene diisocyanate (TDI) can be conjugated with an amine at the nanoclay surface to form a urethane bond, Other free isocyanates may be more reactive with the polymer hydroxyl end groups.

In accordance with some embodiments of the present invention, nanoclay hydroxyl groups are used as nucleation sites for ring opening polymerization, which is further reacted to form lactones such as L-lactide, D-lactide, D, L-lactide and epsilon-capro The lactone is opened. Polymer conjugation on the nanoclay surface forms a polymer brush perpendicular to the surface of the nanoclay particles, which contributes to homogeneous particle dispersion through polymer processing by extrusion as well as stable separation of the particles.

According to one embodiment, the amount of nanoclay is about 20-30% w / w of the nanocomposite layer. According to one embodiment, the amount of nanoclay is about 15-20% w / w of the nanocomposite layer. According to one embodiment, the amount of nanoclay is about 10-15% w / w of the nanocomposite layer. According to one embodiment, the amount of nanoclay is about 5-10% w / w of the nanocomposite layer. According to one embodiment, the amount of nanoclay is about 1-5% w / w of the nanocomposite layer. According to one embodiment, the amount of nanoclay is less than about 20% w / w of the nanocomposite layer. According to one embodiment, the amount of nanoclay is less than about 15% w / w of the nanocomposite layer.

According to one embodiment, the biodegradable sheet of the present invention comprises at least one outer layer which is a multilayer laminate based on a biodegradable blend. According to a further embodiment, the biodegradable sheet of the present invention comprises at least one inner biodegradable nanocomposite layer. According to some embodiments, the biodegradable sheet comprises a gas barrier material, such as at least one inner core layer of polyvinyl alcohol (PVOH). According to some embodiments, the biodegradable sheet comprises two or more inner core layers of a gas barrier material, such as PVOH. Highly polar gas barrier materials, such as PVOH, exhibit weak interactions with low polarity gases such as oxygen and carbon dioxide, which reduces the permeability of the gas through the sheet with the crystalline zone in the sheet.

According to some embodiments of the present invention, the biodegradable sheet comprises PVOH and nanoclay dispersed in one or more of the layers described above.

According to some embodiments, the biodegradable sheet comprises an outer laminate layer, an inner nanocomposite layer, and an inner core layer. Such biodegradable sheets provide a low permeability of the gas.

According to one embodiment, a compatibilizer is added to the biodegradable sheet. The compatibilizer is added to improve adhesion between the different layers of the multi-layer biodegradable sheet. According to one embodiment, the compatibilizer is based on PBSA grafted with maleic anhydride which is a monomer commonly known for grafting, which is used for the modification of polyolefins. According to one embodiment, PBSA is grafted with maleic anhydride in a twin-screw extruder using a continuous flow of nitrogen. According to one embodiment, the grafting is initiated by initiators such as dicumyl peroxide, benzoyl peroxide and 2,2-azobis (isobutyronitrile). According to one embodiment, a mixture of PBSA, about 3% maleic anhydride and about 1% dicumyl peroxide is extruded to obtain PBSA grafted with maleic anhydride.

According to one embodiment, a mixture of PVOH, about 1% maleic anhydride and about 0.3% 2,2-azobis (isobutyronitrile) is extruded to obtain a PVOH grafted with maleic anhydride. According to one embodiment, a mixture of PVOH, about 0.5% maleic anhydride and about 0.1% 2,2-azobis (isobutyronitrile) is extruded to obtain a PVOH grafted with maleic anhydride.

According to one embodiment, a mixture of PVOH and highly branched PBS and a mixture of about 1% maleic anhydride and about 0.3% 2,2-azobis (isobutyronitrile) to obtain a PVOH grafted with maleic anhydride compound with PBS Is extruded. According to one embodiment, a mixture of PVOH and highly branched PBS and a mixture of about 0.5% maleic anhydride and about 0.1% 2,2-azobis (isobutyronitrile) in order to obtain PVOH grafted with a maleic anhydride compound with PBS Is extruded.

According to one embodiment, the amount of compatibilizer added to the PBSA layer is at most 10% w / w. According to one embodiment, the amount of compatibilizer added to the PBSA layer is at most 5% w / w. According to another embodiment, the amount of compatibilizer added to the PBSA layer is at most 4% w / w. According to another embodiment, the amount of compatibilizer added to the PBSA layer is at most 3% w / w. According to another embodiment, the amount of compatibilizer added to the PBSA layer is at most 2% w / w. According to another embodiment, the amount of compatibilizer added to the PBSA layer is at most 1% w / w. According to another embodiment, the amount of compatibilizer added to the PBSA layer is in the range of 2-4%.

According to one embodiment, the amount of compatibilizer added to the PVOH layer is at most 10% w / w. According to one embodiment, the amount of compatibilizer added to the PVOH layer is at most 5% w / w. According to another embodiment, the amount of compatibilizer added to the PVOH layer is at most 4% w / w. According to another embodiment, the amount of compatibilizer added to the PVOH layer is up to 3% w / w. According to another embodiment, the amount of compatibilizer added to the PVOH layer is at most 2% w / w. According to another embodiment, the amount of compatibilizer added to the PVOH layer is at most 1% w / w. According to another embodiment, the amount of compatibilizer added to the PVOH layer is in the range of 2-4% w / w maximum.

In accordance with some embodiments, the biodegradable sheet of the present invention may further comprise an inorganic particulate filler, a fiber, an organic filler, or a combination thereof in order to reduce self-adhesion, reduce cost, and increase the modulus (Young's modulus) .

Examples of inorganic particulate fillers are gravel, rock powder, bauxite, granite, limestone, sandstone, glass beads, aerogels, zeolites, mica, clay, alumina, silica, kaolin, microspheres, hollow glass spheres, porous ceramic spheres, (Crystalline calcium silicate gel), a lightweight expansion clay, a calcium carbonate, a calcium carbonate, a magnesium carbonate, a calcium carbonate, a calcium carbonate, a calcium carbonate, Pearlite, vermiculite, hydrated cement particles hydrated or not hydrated, pumice, zeolite, pearlite, ore, minerals, and other geological materials. (Such as glass, polymers and metals), fillings, pellets, flakes and powders (such as microsilica) as well as combinations thereof, as well as combinations thereof, such as metals and metal alloys (e.g., stainless steel, iron and copper) , Can be added to the polymer blend.

Examples of organic fillers include, but are not limited to, seagel, cork, seed, gelatin, wood powder, sawdust, finely divided polymer materials, agar-based materials, naturally occurring starch granules, pregelatinized and dried starches, . The organic filler may also comprise one or more suitable synthetic polymers.

Fibers can be added to the moldable mixture to increase flexural strength and tensile strength, as well as flexibility, ductility, warpability, cohesiveness, stretchability, deflectivity, toughness and breakdown energy of the resulting sheet and article. Fibers that may be included in the polymer blend include naturally occurring organic fibers, such as wood fibers, plant leaves, and cellulosic fibers extracted from plant stems. In addition, inorganic fibers made from glass, graphite, silica, ceramics, rock wool, or metallic materials can also be used. Preferred fibers include cotton, wood fibers (both hardwood or softwood fibers, examples of which include southern hardwood and southern pine), flax, abaca, sisal, ramie, hemp, and bergas, Easy to disassemble under. Even recycled paper fibers can be used in many cases, which are extremely inexpensive and abundant. The fibers may comprise one or more filaments, fabric, mesh or mat, which may be co-extruded, or may be blended or impregnated with the polymer blend of the present invention.

According to a further embodiment, a plasticizer may be added to impart desirable softening and stretching properties as well as to improve processing, such as extrusion. Selective plasticizers that may be used in accordance with the present invention include, but are not limited to, soybean oil, castor oil, TWEEN 20, TWEEN 40, TWEEN 60, TWEEN 80, TWEEN 85, sorbitan monolaurate, sorbitan monooleate, sorbitan N, N-ethylene bis-oleamide, polymeric plasticizers, such as poly (1,6 (meth) acrylate, naphthalene diisocyanate), sorbitan trioleate, sorbitan monostearate, PEG, PEG derivatives, -Hexamethylene adipate), and other compatible low molecular weight polymers.

According to some embodiments, a salt of a fatty acid, for example, a lubricant such as magnesium stearate, may also be included in the biodegradable sheet of the present invention.

According to a further embodiment, the biodegradable sheets of the present invention may be textured by embossing, crimping, quilting or otherwise to improve their physical properties.

The biodegradable sheet of the present invention comprises a suitable number of layers. According to one embodiment, the biodegradable sheet of the present invention comprises one layer. According to another embodiment, the biodegradable sheet of the present invention comprises two layers. According to another embodiment, the biodegradable sheet of the present invention comprises three layers. According to another embodiment, the biodegradable sheet of the present invention comprises four layers. According to another embodiment, the biodegradable sheet of the present invention comprises five layers.

According to some embodiments, the biodegradable sheet of the present invention has a preferred thickness. According to some embodiments, the thickness of the sheet is in the range of 20-300 microns. When the sheet is made from a composition having a relatively high concentration of particulate filler particles that can protrude from the surface of the sheet, the measured thickness will typically be 10-100% greater than the calculated thickness. This phenomenon is particularly noticeable when filler particles having particle size diameters larger than the thickness of the polymer matrix are used in significant amounts.

According to some embodiments, the thickness of the one-layer sheet is about 40-60 microns. According to some embodiments, the thickness of the one-layer sheet is about 50 microns. According to some embodiments, the thickness of the three-layer sheet is about 90-110 microns. According to some embodiments, the thickness of the three-layer sheet is about 100 microns. According to some embodiments, the biodegradable sheet of the present invention has low haze.

The biodegradable sheet of the present invention can be prepared using suitable means. According to a particular embodiment, the biodegradable polymer used in accordance with the present invention may be extruded (either single or co-extrusion), blow-molded, cast, or otherwise formed into a sheet for use in a wide variety of packaging materials , Or they can be shaped into shaped articles. According to some embodiments, known blow molding devices known in the art of mixing, extruding, blowing, injection molding, and thermoplastic are suitable for use in forming the biodegradable sheet of the present invention. In one embodiment of the present invention, the sheet may be blown-formed into a variety of shapes including the shape of the bottle. According to one embodiment of the invention, a biodegradable sheet is prepared by combining the raw biopolymer with possible additives and then producing the sheet in a cast extruder. Once the biodegradable sheet is produced, it is post-treated by hot sealing, in some embodiments to connect two parts of the same sheet or two separate sheets, thereby producing pockets, pouches, and the like. According to a further embodiment, the biodegradable sheet of the present invention is coated with any suitable coating while ensuring that the final product remains biodegradable.

According to a further embodiment, the one-layer biodegradable sheet of the present invention comprises about 20% w / w PLA and about 80% w / w PBS. According to a further embodiment, the biodegradable sheet of the present invention comprises about 20% w / w PLA, about 40% w / w PBS and about 40% w / w novamont CF. According to a further embodiment, the biodegradable sheet of the present invention comprises about 33% w / w PLA, about 33% w / w PBS and about 33% w / w Ecoflex.

According to a further embodiment, the one-layer biodegradable sheet of the present invention consists of about 20% w / w PLA and about 80% w / w PBS. According to a further embodiment, the biodegradable sheet of the present invention consists of about 20% w / w PLA, about 40% w / w PBS and about 40% w / w novamont CF. According to a further embodiment, the biodegradable sheet of the present invention consists of about 33% w / w PLA, about 33% w / w PBS and about 33% w / w Ecoflex.

According to a further embodiment, the multilayer biodegradable sheet of the present invention comprises three layers, wherein layer 2 is interposed between layers 1 and 3 such that layers 1 and 3 lie outside the sheet and directly And layer 2 is located between them:

Layer 1: contains about 33.3% w / w PLA, 33.3% w / w PBS and 33.3% w / w Ecoflex;

Layer 2: contains about 100% w / w PHA; And

Layer 3: contains about 33.3% w / w PLA, 33.3% w / w PBS and 33.3% w / w Ecoflex.

According to a further embodiment, the multilayer biodegradable sheet of the present invention comprises three layers:

Layer 1: contains about 33.3% w / w PLA, 33.3% w / w PBSA and 33.3% w / w PBAT;

Layer 2: contains about 100% w / w PBAT; And

Layer 3: contains about 33.3% w / w PLA, 33.3% w / w PBSA and 33.3% w / w PBAT.

According to a further embodiment, the multilayer biodegradable sheet of the present invention comprises three layers:

Layer 1: composed of about 33.3% w / w PLA, 33.3% w / w PBS and 33.3% w / w Ecoflex;

Layer 2: composed of about 100% w / w PHA; And

Layer 3: composed of about 33.3% w / w PLA, 33.3% w / w PBS and 33.3% w / w Ecoflex.

According to a further embodiment, the multilayer biodegradable sheet of the present invention comprises three layers:

Layer 1: composed of about 33.3% w / w PLA, 33.3% w / w PBSA and 33.3% w / w PBAT;

Layer 2: composed of about 100% w / w PBAT; And

Layer 3: composed of about 33.3% w / w PLA, 33.3% w / w PBSA and 33.3% w / w PBAT.

According to a further embodiment, the single layer biodegradable sheet consists of about 75% PBSA and about 25% PLA. According to some embodiments, the multi-layer biodegradable sheet of the present invention consists of the following three, five, or more layers. According to some embodiments, the outer layer consists of about 25% w / w PLA and about 75% w / w PBSA. According to some embodiments, the PVOH layer is included as a core layer and interposed between the biodegradable polymer layer and the existing nanocomposite layer. According to some embodiments, at least one layer is composed of a 100% biodegradable polymer, such as PBSA. According to some embodiments, the biodegradable sheet comprises at least one inner layer comprised of PBSA and about 10-15% w / w nanoclay. According to some embodiments, the biodegradable sheet comprises at least one inner layer comprised of PBSA and about 5-10% w / w nanoclay. According to some embodiments, the biodegradable sheet comprises at least one inner layer comprised of PBSA and about 0-5% w / w nanoclay. According to some embodiments, the biodegradable sheet comprises at least one inner layer comprised of PBSA and about 15-20% w / w nanoclay. According to some embodiments, the biodegradable sheet comprises at least one inner layer comprised of PBSA and about 20-25% w / w nanoclay. According to a further embodiment, the PBSA can be replaced with a suitable biodegradable polymer blend. According to a further embodiment, the multilayer biodegradable sheet of the present invention consists of three layers:

Layer 1: composed of about 25% w / w PLA and about 75% w / w PBSA;

Layer 2: composed of about 100% w / w PBSA; And

Layer 3: composed of about 25% w / w PLA and about 75% w / w PBSA.

According to a further embodiment, the multilayer biodegradable sheet of the present invention consists of three layers:

Layer 1: composed of about 75% w / w PLA and about 25% w / w PBSA;

Layer 2: composed of about 100% w / w PBSA; And

Layer 3: composed of about 75% w / w PLA and about 25% w / w PBSA.

According to one embodiment, the thicknesses of the three layers are all the same.

According to a further embodiment, the multilayer biodegradable sheet of the present invention consists of the following five layers:

Layer 1: composed of about 25% w / w PLA and about 75% w / w PBSA;

Layer 2: composed of about 100% w / w PBSA;

Layer 3: composed of about 100% w / w PVOH;

Layer 4: composed of about 100% w / w PBSA; And

Layer 5: composed of about 25% w / w PLA and about 75% w / w PBSA.

According to one embodiment, the thickness of layers 1 and 5 is about 30% of the total thickness of the sheet, the thickness of layers 2 and 4 is about 15% of the total thickness of the sheet, It is about 10%.

According to a further embodiment, the multilayer biodegradable sheet of the present invention consists of the following five layers:

Layer 1: composed of about 25% w / w PLA and about 75% w / w PBSA;

Layer 2: composed of about 90-85% PBSA and about 10-15% w / w nanoclay;

Layer 3: composed of about 100% w / w PVOH;

Layer 4: composed of about 90-85% PBSA and about 10-15% w / w nanoclay; And

Layer 5: composed of about 25% w / w PLA and about 75% w / w PBSA.

Although specific examples of single, triple and five-layer sheets are given here, embodiments of the present invention also relate to biodegradable sheets comprising as many layers as possible.

According to another embodiment, the biodegradable composition of the present invention is suitable for injection molding. Injection molding is used in accordance with the present invention to produce a suitable form comprising means for removing liquid from a beverage container, such as spout, straw, cap-covered opening, and the like. The physical and mechanical properties of the injection-molded biodegradable materials according to the present invention are as follows:

Specific gravity 1.0-1.5 ASTM D792

Melt volume ratio (190 占 폚 / 2.16 kg) [cm3 / 10 minutes] 3.0-8.0 ASTM D1238

Melt flow rate (190 占 폚 / 2.16 kg) [g / 10 min] 4.0-9.0 ASTM D1238

Tensile Strength and Break (MPa) 30-50 ASTM D882

Tensile Ratio (MPa) 800-1200 ASTM D882

Tensile elongation (%) 200-400 ASTM D882

According to some embodiments of the invention, the biodegradable composition to be molded by injection is made from 75% PBSA and 25% PLA. The physical and mechanical properties of this composition are as follows:

Specific Gravity 1.25 ASTM D792

(190 占 폚 / 2.16 kg) [cm < 3 > / 10 minutes] 3.9 ASTM D 1238

Melt flow rate (190 占 폚 / 2.16 kg) [g / 10 min] 4.2 ASTM D1238

Tensile Strength and Break (MPa) 32 ASTM D882

Tensile Ratio (MPa) 894 ASTM D882

Tensile elongation (%) 339 ASTM D882

The biodegradable sheet of the present invention can be used in applications requiring such a sheet. According to one embodiment, the biodegradable sheet of the present invention is used in the manufacture of containers for liquids comprising water, beverage and liquid food materials.

According to one embodiment of the present invention, there is provided a removable beverage container package comprising a plurality of possible volumes of a plurality of container units formed in an adjacent fashion, each of which can be removed on demand. Separate beverage container packaging may be made of biodegradable materials. In one embodiment of the invention, the separable beverage container package is made of the biodegradable sheet described herein. According to one embodiment, the container units are attached to one another in a side-by-side configuration. According to another embodiment, the container units are attached to one another such that one unit bottom is attached to the top of the other unit. According to a further embodiment, the separable beverage container package of the present invention comprises a plurality of container units, some of which may have different volumes and shapes. According to a further embodiment, at least two of the container units have different volumes. According to one embodiment, at least one of the container units is asymmetric. According to a further embodiment, two or more of the container units are asymmetric.

Each container (e. G., A pouch, bag or other type of essentially flexible container) includes a biodegradable material that is flexible and sufficiently impermeable, such as two sheets of the biodegradable composition described in detail herein. According to one embodiment, biodegradable sheets are heat sealed along a defined line to create individual container units, which are separated from each other by a non-perforated line that allows individual container units to be physically separated from each other. According to some embodiments, the perforations are modified to provide container units having different volumes corresponding to the amount of liquid that is regularly consumed by family members. According to one embodiment, the perforations between the two container units ensure that there is no excess material found between the container units that is not part of the container unit itself, that is, there is no material that is discarded once it has been removed.

A plurality of interconnected container units are referred to herein as arrays. The array of the present invention includes a certain number of container units, some of which may have different shapes and / or volumes. According to one embodiment, the volume of each container unit is in the range of 100-500 ml. According to a further embodiment, the volume of each container unit is in the range of 200-350 ml. According to one embodiment, the shape of the at least one container unit is triangular. According to another embodiment, the shape of the at least one container unit is pyramidal.

According to one embodiment, the array is terminated as a latch for effective storage (see, e.g., Figures 6a-d and 7a-d). According to one embodiment, such a latch is formed as a round hole in the array. According to the present invention, each container unit comprises a liquid storage compartment and means for removing liquid therefrom. The means for removing liquid from the compartments can be a straw (e.g., see Figs. 1, 2a-c, 6a-d and 7a-d), a conduit (e.g., see Figs. 3a-e), a snout, (See, e. G., Figs. 3F and 4A), an opening closed by a cap, and a collapsible unit (see Figs. 5A and 5B, for example) do. According to some embodiments, the compartment does not include an opening, rather the opening is formed by movement of an element, such as a cap, attached to the compartment.

According to some embodiments, each container unit comprises a liquid storage compartment and a straw. According to one embodiment, Straw is hermetically sealed between the sheets of the compartment in such a way that it has two pieces, an inner piece found inside the compartment and an outer piece found outside the compartment. According to a further embodiment, each container unit further comprises a sealing edge for sealing the outer pieces of the straw which are also interspersed between the sheets of the sealing edge. According to some embodiments, a perforation line is positioned between the sealing edge and the compartment, which tearing the sealing edge to expose the inner piece of the straw.

According to one embodiment of the present invention, the straw includes two opposed members positioned between the outer and inner segments of the straw. These members are attached to the biodegradable sheet of the container unit, for example by hot sealing them between the two sheets, thus preventing movement of the straw and leakage from around the straw. According to one embodiment, these members are tapered to facilitate attachment to the container unit.

According to a further embodiment, the container unit comprises a liquid storage compartment and a conduit through which liquid can be emptied from the compartment. According to one embodiment, the conduit is formed from a series of biodegradable sheets forming the compartment. According to one embodiment, the conduit is sealed at the end, for example by heat, and includes a perforated line which, when desired, opens the conduit and helps to remove liquid from the compartment. According to one embodiment, the conduit is folded over when not in use. According to a further embodiment, the conduit is attached to the side of the compartment when not in use.

According to the invention, the container units are attached to each other at appropriate locations on each container unit. According to one embodiment of the present invention, the container units are attached to each other in a side-by-side manner, with the opening of each unit positioned in the proper direction. According to one embodiment, when the container units are connected in a side-by-side manner, the opening of each container is up or down. According to one embodiment, the openings of the container units are alternately, that is, the first is directed above (or below) and the next is below (or above). According to a further embodiment, a certain number of openings are located on the side, front or back side of the container unit. According to the present invention, these openings may comprise a straw as described above.

According to another embodiment, a biodegradable sheet is used to produce a large-volume pouch that can be used as a substitute for a large plastic bottle supplied to a water purifier. In this case, the pouch will have a snout that completely coincides with the inlet of the water purifier. The pouch will have a latch member to allow the pouch to hang, thereby allowing the mouth to be at the bottom, allowing the water to escape the pouch by gravity. According to one embodiment, the snout is sealed by a flexible material that can be pierced by a suitable end extending from the mouth of the water purifier prior to use. Alternatively, the pouch can be inserted into an adapter that receives the pouch, guides it towards the piercing end, and locks it in place unless the pouch is emptied.

Figure 1 illustrates the construction of an exemplary array of different volumes of container units (also referred to herein as pouches) formed in an adjacent, side-by-side fashion, each of which may be detached on demand. The array 10 can include a plurality of pouches of different volumes (in this example, volumes of 200 ml, 250, 300, and 350 ml), whereby the entire array is limited to a size of 20 x 37 cm. Each pouch is separated from the neighboring pouches by a perforated line of curvature that allows an optimal separation of confined areas between different pouches. Each individual pouch may be marked to indicate its volume and contents, such as pouch 101.

2A illustrates a layout of a single pouch according to one embodiment of the present invention. The pouch 101 that is detached from the array 10 is also located between the sheets of the sealing edge 104 and the interior portion of the straw 103 sealingly interspersed between the sheets of the compartment 102, And a sealing edge 104 for sealing the outer piece of the sealed straw 103. A perforated line 105 is applied between the sealing edge 104 and the compartment 102.

The user may tear the sealing edge 104 along the perforation line 105 and remove the sealing edge 104 from the outer piece of the straw 103, as shown in FIG. 2B. This allows the user to drink the fluid through an external piece of straw as shown in Figure 2c.

Figure 2d shows the layout of an internal straw piece according to an embodiment of the invention. The straw segment 103 has two opposing tapered members 103a and 103b extending outwardly and thereby can be attached (i. E., Interposed between) biodegradable impermeable sheets defining the compartments.

Figure 2E shows a cross-sectional view of a sealed inner straw segment in accordance with one embodiment of the present invention. Two opposed tapered members 103a and 103b are pressed between two opposed biodegradable, impermeable sheets 200, whereby a sealing pressure is obtained and both the movement of the straw and the leakage from its surroundings are prevented.

Figure 3a shows the layout of six pouch arrays in accordance with one embodiment of the present invention. If desired, each pouch 300 may be detached from the array along the corresponding perforation line 105 at any time. As shown in FIG. 3B (front view), the fluid storage section 301 of each single pouch 300 is terminated by a flat conduit 302 having a sealing edge 303 at its distal end. The flattened conduit 302 is bent (e.g., to form a U-shape) before use, with the sealing edge 303 attached to the side wall of the pouch 300 (side view). Perforated line 105 may be either full length or partial length.

When the user wishes to drink, the user first removes the sealing edge 303 from the sidewall and straightens the flat conduit 302, as shown in Figure 3c. Next, the user tears the sealing edge 303 along the perforated line 105 and removes the sealing edge 303 from the far end of the flattened conduit 302, thereby breaking the seal and opening the proximal end, To form a straw fragment. The user can now drink the fluid through the distal end as shown in Figure 3e. The sealing edge 303 as well as the straw segments can be made of the same biodegradable material from which the pouch is made.

Figure 3f shows an array of several container units in which the openings are alternately in an up-down position by being attached to one another in a side-by-side fashion. As shown in FIG. 3F, only a central portion of the various container units are attached to each other.

4A shows a layout of a single pouch according to another embodiment of the present invention. The pouch 400 includes a clipped section 401 for storing liquid which terminates in a flat surface 402 from which the conduit fragment 403 extends outwardly. The proximal end of the conduit 103 terminates in a sealing disc (not shown) that is part of the flat surface 402. The seal disc also has several nicks formed therein to accommodate the mating protrusions. The seal master is attached to the edge of the conduit segment 403 by a relatively weak layer sealing the segment 401 and can be destroyed by applying a rotational shear force thereto. The shearing force may be applied by the upper cover 404 including several protrusions 405. [ These protrusions 405 are designed to mate with the formed niche so that when the cover 404 is attached to the distal end of the conduit fragment 403, the niche formed in the seal disc receives the mated protrusion 405, But remains unattached and remains attached thereto (e.g., by unidirectional elastic connection). According to this embodiment, when the user wishes to drink, the user must rotate the top cover 404, which breaks the weak layer and disconnects the seal disc from the edge of the conduit segment 403. According to this embodiment, the seal is broken, and the user now removes the top cover with the sealing disc attached to the top cover. Thus, the user can drink fluid through the conduit segment 403 as shown in FIG. 4B. Alternatively, the clipping of the compartment can be removed by placing the top cover in the center of the side wall, as shown in Figure 4c. In this case, the pouch can be placed on a flat support. In both configurations, the top cover can be reused (screw type) to seal the conduit segment 403.

4D is a sectional view of the upper cover sealing structure. In this construction, the top cover 406 is screwed onto the top of the thermally welded conduit segment 403 at the edge of the biodegradable impermeable sheet 407, whereby an impermeable seal is obtained.

Figures 5A and 5B illustrate the layout of a single pouch with a straw foldable in a pivot according to another embodiment of the present invention. The pouch 500 includes a rigid arcuate member 501 attached to an edge of the pouch 500. The arcuate member 501 includes an elongated groove 502 (cradle) for receiving a stiff straw 503 that can be folded in a corresponding pivot axis, with a tubular conduit allowing fluid to flow. In addition, the arcuate member 501 includes a spherical tab (not shown) at its end with a hole in the cavity side of the pouch. This spherical tap is also used as a joint in which the straw 503 can be turned around. As long as the pouch is stored, the straw 503 is placed in the groove 502 (shown in Fig. 5A), and the tubular duct does not overlap with the hole in the spherical tab. In this position, the pouch is sealed. When the straw 503 is lifted to its vertical position (as shown in FIG. 5B), the tubular conduit overlaps the hole in the spherical tab, and fluid flows from the pouch through the straw 503 to the user ' s mouth . The pouch can be sealed again by folding the straw 503 back to the cradle after use. It is also possible to add a sealing sheet at the top of the hole to increase the sealing level before use and to include the perforation end at the end of the straw 503 so that the straw 503 is lifted to its vertical position The sealing sheet will be punched.

Figures 6a, 6b, 6c and 6d illustrate an array of four container units, all of which are closed. 6A is a schematic view of the array, which includes four detachable container units separated from one another by a perforated line. Further, as shown in Fig. 6A, the container units each include an upper straw (closed in this figure) and a lower hole, whereby the container unit can take on a kind of hook, rope, twin, and the like. Figure 6b is a front view of the array, Figure 6c is a side view of the array, and Figure 6d is a top view of the array.

Figures 7a, 7b and 7c show the same array as shown in Figures 6a-d, but in Figures 7a-d the container units are all open and have a straw protruding from the top of each unit. Specifically, Figure 7A is a schematic view of the array, Figure 7B is a front view of the array, Figure 7C is a side view of the array, and Figure 7D is a top view of the array.

According to another embodiment, the biodegradable sheet is made of two laminated layers. The first layer is an inner layer, made of 10-50 袖 m thick PLA in contact with liquid. The second layer is an outer layer, made of 50-150 micron thick starch exposed to air. The two layers are attached to each other by an adhesive layer, the weight of which is less than 1% of the total weight of the laminated layers. This combination is unique due to the fact that the laminated sheet is sufficiently impermeable to hold the liquid and is flexible enough to allow efficient and convenient manufacture of the pouch.

According to another embodiment, a biodegradable sheet that is highly flexible, transparent, and suitable for liquid delivery can be made from additional biodegradable polyesters such as polybutylene succinate (PBS), polybutylene succinate adipate (PBSA), poly Tetramethylene adipate-coterephthalate) (PTAT), and blended polylactic acid (PLA) with a thermoplastic starch blend.

Polylactic acid is poly (L-lactic acid) wherein the structural unit is L-lactic acid; Poly (D-lactic acid) wherein the structural unit is D-lactic acid; Poly (DL-lactic acid), a copolymer of L-lactic acid and D-lactic acid; And mixtures thereof.

The different combinations of the above-mentioned polymers should be melt-compounded using a twin-screw extruder. The polymer blends are extruded in the form of strands to form pellets. The pellets contain a physical mixture (blend) of different polymers used. The blends are then extruded in a cast or blow-molded film extruder to obtain a film or sheet. Metallized laminates of the polymers described above can be obtained using an aluminum film or aluminum deposition to increase the barrier of the film and sheet.

Various aspects of the invention will be described in more detail in the following examples with reference to examples of the invention, which are not to be construed as limiting the scope of the invention.

Example

Example  One

Single layer biodegradable sheet

The monolayer sheets referred to herein were all 50 microns thick.

Sheet # 1: A single layer biodegradable sheet composed of 33.3% w / w PLA, 33.3% w / w PBS and 33.3% w / w Ecoflex was prepared as follows:

A. Melt extrusion compounding step:

1. 166.7 gr PLA, 166.7 gr PBS and 166.7 gr Ecoflex were dried under vacuum at a temperature of 50 캜 overnight;

2. The dried polymer was dry blended and placed in a 2-screw PRISM compounding unit;

3. The polymer was melt-extruded in a PRISM compounding machine set to the following profile:

i) Temperature profile: 170-175-180-185-190 DEG C (die set at 190 DEG C);

ii) screw speed: 250 rpm; And

iii) Pressure: 15-25 bar.

B. Casting Extrusion step:

1. The melt extruded material was dried under vacuum at a temperature of < RTI ID = 0.0 > 50 C < / RTI &

2. The material was placed in a Randcastle extruder set to the following profile:

i) 170-180-190 DEG C -180 DEG C - adapter; 185 ° C - feed block; Die-185 占 폚;

ii) screw speed: 80 rpm; And

iii) Head pressure: 590 bar.

The measured properties of sheet # 1 were as follows: at full load, the stress was 25 MPa, the breaking strain was 415%, and the Young's modulus was 679 MPa.

Sheet # 2: A single layer biodegradable sheet composed of 20% w / w PLA and 80% w / w PBS was prepared using the same procedure as described in Genesis for Sheet # 1 and the amount of polymer used was 100gr PLA and 400gr PBS. The measured physical properties of sheet # 2 were as follows: the stress at the maximum load was 47 MPa, the breaking strain was 731%, and the Young's modulus was 569 MPa.

Sheet # 3: A single layer biodegradable sheet composed of 20% w / w PLA, 40% w / w PBS and 40% Novamont CF was prepared using the same procedure as described for the sheet # 1, The amounts were 100gr PLA, 200gr PBS and 200gr Novamont. The measured physical properties of Sheet # 3 were as follows: the stress at the maximum load was 33 MPa, the breaking strain was 579%, and the Young's modulus was 603 MPa.

Sheet # 4: A single layer biodegradable sheet composed of 60% w / w PLA and 40% w / w PBS was prepared using the same procedure as described in Genesis for Sheet # 1 and the amount of polymer used was 300 gr PLA and 200 gr PBS. The measured physical properties of sheet # 4 were as follows: the stress at the maximum load was 40 MPa, the breaking strain was 240%, and the Young's modulus was 1274 MPa.

Sheet # 5: A single layer biodegradable sheet composed of 55% w / w PLA and 45% w / w PBS was prepared using the same procedure as described in Genesis for Sheet # 1, the amount of polymer used was 275 gr PLA and 225 gr PBS. The measured physical properties of sheet # 5 were as follows: the stress at the maximum load was 45 MPa, the breaking strain was 4%, and the Young's modulus was 1414 MPa.

As evidenced by their physical properties detailed above, sheets # 1-3 are beneficial single-layer biodegradable sheets according to the present invention. Further, as described in detail above, the compositions of sheets # 4 and # 5 are very similar, but they have a great difference in physical properties, particularly in breaking strain. Therefore, it is clearly necessary to carry out many experiments in order to reach desired properties.

Example  2

3-layer biodegradable sheet

All three-layer sheets referred to herein were 100 microns in total.

Sheet # 6: A three-layer biodegradable sheet was prepared according to the procedure described above for sheet # 1, and the weight of each layer constitutes 1/3 of the weight of the final sheet. The three-layer sheet # 6 consists of the following three layers:

Layer 1: 33.3% w / w PLA, 33.3% w / w PBS and 33.3% w / w Ecoflex

Layer 2: 100% w / w PHA

Layer 3: 33.3% w / w PLA, 33.3% w / w PBS and 33.3% w / w Ecoflex

The measured properties of sheet # 6 were as follows: the stress at the maximum load was 20 MPa, the breaking strain was 558%, and the Young's modulus was 675 MPa.

Sheet # 7: A three-layer biodegradable sheet was prepared according to the procedure described above for Sheet # 1, and the weight of each layer constitutes 1/3 of the weight of the final sheet. The three-layer sheet # 7 consists of the following three layers:

Layer 1: 33.3% w / w PLA, 33.3% w / w PBSA and 33.3% w / w PBAT

Layer 2: 100% w / w PBAT

Layer 3: 33.3% w / w PLA, 33.3% w / w PBSA and 33.3% w / w PBAT

The measured physical properties of Sheet # 7 were as follows: the stress at the maximum load was 30 MPa, the breaking strain was 618%, and the Young's modulus was 391 MPa.

Sheet # 8: A three-layer biodegradable sheet was prepared according to the procedure described above for sheet # 1, and the weight of each layer constitutes 1/3 of the weight of the final sheet. The three-layer sheet # 8 consists of the following three layers:

Layer 1: 100% w / w PBS

Layer 2: 60% w / w PLA and 40% w / w PBS

Layer 3: 100% w / w PBS

The measured physical properties of sheet # 8 were as follows: the stress at the maximum load was 44 MPa, the breaking strain was 4.1%, and the Young's modulus was 1374 MPa.

Sheet # 9: A three-layer biodegradable sheet was prepared according to the procedure described above for sheet # 1, and the weight of each layer constitutes 1/3 of the weight of the final sheet. The three-layer sheet # 9 consists of the following three layers:

Layer 1: 100% w / w Ecoflex

Layer 2: 50% w / w PLA and 50% w / w PBAT

Layer 3: 100% w / w Ecoflex

The measured physical properties of sheet # 9 were as follows: the stress at the maximum load was 38 MPa, the breaking strain was 559%, and the Young's modulus was 837 MPa.

As evidenced by their physical properties detailed above, sheets # 6-7 are beneficial three-layer biodegradable sheets according to the present invention.

In all of the sheets, layer 2 is interposed between layer 1 and layer 3, whereby layers 1 and 3 are outside the three-layer biodegradable sheet and are in contact with the external atmosphere, layer 2 is positioned between them It does not come into contact with atmosphere.

Example  3

The physical, mechanical, thermal and thermal properties of single, three and five layer biodegradable sheets Barrier  characteristic

Sheet # 10: A single layer biodegradable sheet composed of 25% w / w PLA and 75% w / w PBSA was prepared using the same procedure as described above for Sheet # 1, the amount of polymer used was 125 gr PLA and 375 gr PBS. The measured physical properties, mechanical properties, thermal properties, and barrier properties of Sheet # 10 were as follows:

Properties:

Specific Gravity 1.25 ASTM D792

Melt Volume Rate (190 占 폚 / 2.16 kg) [cm3 / 10 min] 3.9 ASTM D1238

Melt flow rate (190 占 폚 / 2.16 kg) [g / 10 min] 4.2 ASTM D1238

Mechanical properties:

Tensile strength at break (MPa) 32 ASTM D882

Tensile Ratio (MPa) 894 ASTM D882

Tensile elongation (%) 339 ASTM D882

Notch type Izod impact (J / m) 536 ASTM D256

Thermal properties:

Heat distortion temperature HDT [℃ / 18.5kg / ㎠] 45 ASTM D648

Barrier characteristics:

OTR (oxygen permeable from the bottle) 0.3 cc / pack / day

Sheet # 11: A three-layer biodegradable sheet was prepared according to the procedure described above for sheet # 1, and the weight of each layer constitutes 1/3 of the weight of the final sheet. The three-layer sheet # 11 consists of the following three layers:

Layer 1: composed of about 25% w / w PLA and about 75% w / w PBSA;

Layer 2: composed of about 100% w / w PBSA; And

Layer 3: composed of about 25% w / w PLA and about 75% w / w PBSA.

The measured physical properties, mechanical properties and barrier properties of Sheet # 11 are as follows:

Properties:

Transparency (%) 88

Mechanical properties:

Tensile strength at break, MD (MPa) 24 ASTM D882

Tensile strength at break, TD (MPa) 22 ASTM D882

Tensile Ratio, MD (MPa) 527 ASTM D882

Tensile Ratio, TD (MPa) 392 ASTM D882

Tensile elongation, MD (%) 319 ASTM D882

Tensile elongation, TD (%) 463 ASTM D882

Barrier characteristics:

WVTR [Water permeability, g / (m2 * d)] 48.4 ASTM E96

OTR [cm 3 / (m 2 * d * bar)] 54.1 ASTM D3985

Sheet # 12: A five-layered biodegradable sheet was prepared according to the procedure described above for Sheet # 1, the thickness of each of Layers 1 and 5 constituting about 30% of the total thickness, and the thickness of each of Layers 2 and 4 Constitutes about 15% of the final sheet thickness, and the thickness of layer 3 constitutes about 10% of the final sheet thickness. It is noted that the weight ratios are approximately equal to the thickness ratios since the materials have approximately the same density. The 5th floor sheet # 12 consists of the following five layers:

Layer 1: composed of about 25% w / w PLA and about 75% w / w PBSA;

Layer 2: composed of about 100% w / w PBSA;

Layer 3: composed of about 100% w / w PVOH;

Layer 4: composed of about 100% w / w PBSA; And

Layer 5: composed of about 25% w / w PLA and about 75% w / w PBSA.

The measured physical properties, mechanical properties, and barrier properties of sheet # 12 are as follows:

Properties:

Transparency (%) 88

Mechanical properties:

Tensile strength at break MD (MPa) 32 ASTM D882

Tensile strength at break, TD (MPa) 27 ASTM D882

Tensile Ratio, MD (MPa) 464 ASTM D882

Tensile Ratio, TD (MPa) 596 ASTM D882

Tensile elongation, MD% 687 ASTM D882

Tensile elongation, TD% 447 ASTM D882

Barrier characteristics:

WVTR [g / (m2 * d)] 57.0 ASTM E96

OTR [cm 3 / (m 2 * d * bar)] 2.2 ASTM E3985.

Sheet # 13: A 5-layer biodegradable sheet was prepared according to the procedure described above for sheet # 1, the thickness of each of layers 1 and 5 constituting about 30% of the total thickness, and the thickness of each of layers 2 and 4 Constitutes about 15% of the final sheet thickness, and the thickness of layer 3 constitutes about 10% of the final sheet thickness. It is noted that the weight ratios are approximately equal to the thickness ratios since the materials have approximately the same density. The 5th layer sheet # 13 consists of the following five layers:

Layer 1: composed of about 25% w / w PLA and about 75% w / w PBSA;

Layer 2: composed of PBSA and about 20% w / w nano-kaolin;

Layer 3: about 100% w / w PVOH composition;

Layer 4: composed of PBSA and about 20% w / w nano-kaolin; And

Layer 5: composed of about 25% w / w PLA and about 75% w / w PBSA.

The barrier properties of sheet # 13 were as follows:

Barrier characteristics:

WVTR [g / (m2 * d)] 30.0 ASTM E96

OTR [cm 3 / (m 2 * d * bar)] 2.0 ASTM D3985

As evidenced by the above results, the addition of PVOH to the biodegradable sheet degrades the OTR and the further addition of nanoclay reduces the WVTR.

Example  4

Biodegradability

Sheet # 14: A three-layer biodegradable sheet was prepared according to the procedure described above for sheet # 1, and the weight of each layer constitutes 1/3 of the weight of the final sheet. The three-layer sheet # 14 consists of the following three layers:

Layer 1: composed of about 75% w / w PLA and about 25% w / w PBSA;

Layer 2: composed of about 100% w / w PBSA; And

Layer 3: composed of about 75% w / w PLA and about 25% w / w PBSA.

In accordance with ISO 14855-2, the reference material used was microcrystalline cellulose. The graph presented in Figure 8 shows the percent decomposition of sheets # 14 (columns N1 and N2) compared to the criteria (columns N3 and N4). The columns of columns N1 and N2 and the columns other than the microcrystalline cellulose of columns N3 and N4 were filled with cob. Throughout this test the temperature of the column was maintained at 58 ° C.

While specific features of the invention have been illustrated and described herein, many modifications, substitutions, changes, and equivalents will now occur to those skilled in the art. Accordingly, the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.

Claims (20)

A biodegradable sheet comprising a gas barrier material. The biodegradable sheet of claim 1, wherein the gas barrier material is a nanoclay. The biodegradable sheet of claim 1, wherein the gas barrier material is polyvinyl alcohol (PVOH). The biodegradable sheet of claim 1, wherein the gas barrier material is nanoclay and PVOH. 3. The biodegradable sheet of claim 2, wherein the nanoclay is based on montmorillonite, vermiculite, nano-kaolin, bentonite, Cloisite or a combination thereof. 3. The biodegradable sheet of claim 2, wherein the nanoclay is dispersed in a bulk of the biodegradable composition. 3. The biodegradable sheet of claim 2, wherein the nanoclay is added to the biodegradable sheet as a separate nanocomposite layer comprising a biodegradable polymer and a nanoclay. The biodegradable sheet of claim 7, wherein the separated nanocomposite layer is an inner layer. 4. The biodegradable sheet according to claim 3, wherein the PVOH is added to the biodegradable sheet as an inner layer. The biodegradable sheet according to claim 3, further comprising a compatibilizer. The biodegradable sheet according to claim 10, wherein the compatibilizing agent is maleic anhydride, benzoyl peroxide or 2,2-azobis (isobutyronitrile). 11. The biodegradable sheet of claim 10, wherein the amount of compatibilizer is about 2-4% w / w of the layer to which the compatibilizer is added. The biodegradable sheet of claim 1, having a water vapor permeability of less than 60 g / (m2 * d). The biodegradable sheet according to claim 1, having an oxygen permeability of less than 3.0 cm 3 / (m 2 * d * bar). The biodegradable sheet according to claim 1, which is composed of the following three layers:
Layer 1: composed of about 20-80% w / w PLA and about 80-20% w / w PBSA;
Layer 2: composed of about 100% w / w PBSA; And
Layer 3: composed of about 20-80% w / w PLA and about 80-20% w / w PBSA. The biodegradable sheet according to claim 1, which is composed of the following five layers:
Layer 1: composed of about 20-80% w / w PLA and about 80-20% w / w PBSA;
Layer 2: composed of about 100% w / w PBSA;
Layer 3: composed of about 100% w / w PVOH;
Layer 4: composed of about 100% w / w PBSA; And
Layer 5: composed of about 20-80% w / w PLA and about 80-20% w / w PBSA. The biodegradable sheet according to claim 1, which is composed of the following five layers:
Layer 1: composed of about 20-80% w / w PLA and about 80-20% w / w PBSA;
Layer 2: composed of about 90-85% PBSA and about 10-15% w / w nanoclay;
Layer 3: composed of about 100% w / w PVOH;
Layer 4: composed of about 90-85% PBSA and about 10-15% w / w nanoclay; And
Layer 5: composed of about 20-80% w / w PLA and about 80-20% w / w PBSA. The biodegradable sheet of claim 1, wherein the degree of degradation is less than 60% after 30 days at a temperature of 58 ° C. A container unit made from the biodegradable sheet according to claim 1, comprising a liquid storage compartment and means for removing liquid from the liquid storage compartment. 20. The container unit of claim 19, further comprising a latch.

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